After a fall or a bump, some bike parts fall into disrepair and need to be replaced or repaired. Beginners and professionals alike look for ways to straighten to save the bike from breakage and their wallet from waste. One popular question on bike forums is, “How do you straighten a cock yourself?”
The unusual name “rooster” can bring a smile. It is otherwise referred to as a “bracket” or “lever.” A bicycle’s cock is the part to which the rear derailleur attaches. Its function is to take all the shock to protect the frame and rear derailleur.
The rooster on a bicycle is made of soft metals, mostly aluminum, so it can easily warp and bend.
If the cock is bent even a millimeter, you already feel that something is definitely wrong with the bike. Often cyclists do not take it into account, and when malfunctions occur, they assume that the problem is in the chain, transmission and any other part.
You can check and align the cock on the bike with the help of a craftsman, as well as on your own. There is nothing complicated about it, just stock a set of tools and allocate some personal time.
Methods of straightening the cock on the bicycle
How to straighten the cock on the bike at home? In fact, everything is very simple. So do not rush to throw out the deformed part and run for a new one.
First, it is worth checking whether the bicycle cock really needs to be repaired. If during the inspection you found out that it needs, then by no means:
- do not use a hammer – it is contraindicated;
- Do not try to melt the metal;
- Do not repair if there are obvious cracks.
Using a hammer can permanently break the soft metal part. And if there are visible cracks, there is no point in repairing it. Melting at home is not even worth discussing.
The cassette and the cock should be parallel
Turn your bike upside down with the wheels. This makes it easier to tell if the cock on your bike is bent. Pay attention to the rear wheel. Inspect the distance between the rooster and the nearest sprocket.
The small sprocket cassette should be parallel to the cock. Of course, a strong deflection will be noticeable immediately. But in some cases, it is better to measure the distance at the two extreme points to compare values.
Note that the cock may be bent in one of two planes. For convenience, we will designate them as:
- horizontal;
- vertical.
Which means you need to check the parallelism in two ways to make sure the rooster is fully functional.
If it is difficult to shift speed gears or the sprocket is missing during adjustment, the deformation of the shape will be noticeable even to the eye.
Tools needed
The tools you will need to check for parallelism are listed below. This set will be enough to make bike repairs and align the part.
The tools needed are:
- eccentric;
- Tapered bushing axles, 2 pieces. One of them under the eccentric. Choose a diameter of 10 mm. An axle with a diameter of 9,5 mm can break threads;
- nuts for axles;
- ruler.
If you do not have these tools in your home, ask a cyclist you know. Usually these parts gather dust in boxes for lack of use.
Straightening the cock on the bicycle: step by step instructions
For convenience, turn the bike over and put it upside down with the wheels. You can also remove the chain. This way it will be much easier to carry out the following steps.
Instructions for preparing the cock (bracket, lever):
- Remove the rear wheel and rear derailleur.
- Put one of the axles (under the eccentric) where the wheel should be. Tighten the nuts. Make sure you push it in as far as it will go on both sides.
- Insert the eccentric pin in the axle and lock it in place.
- Lubricate the threads on the cock from the inside so you don’t accidentally damage them.
- Screw in the second axle. The threads from the cone bushings fit the threads on the cock. Tighten the nuts on both sides so you don’t ruin the part.
Now you need to make sure that the two axes are parallel.
Check in the first plane:
- Measure the distance between the axes at the two extreme points using a ruler.
- Compare the values. If they are the same, good. If they are not the same, then the rooster is crooked in this plane.
- Do not force the axle when measuring. Otherwise you could bend the part more.
Check the second plane:
- The inspection is done by eye. That is why it is important to choose the right position for the check. At first you should only see one axis while the second axis is “hidden” behind it.
- Gradually change the angle of view until you see a gap between the axes. If the gap appears only at one end, then the part is warped. The gap should appear equally along the entire length of the axis.
- To increase the contrast, you can put a white sheet of paper on the back. This will make it easier to determine where the gap appears.
Aligning the rooster:
- Make an effort with your fingers on the axle that is screwed into it. Since the metal is soft, the piece will begin to warp. You don’t need to use a hammer or other tools to align the aluminum piece.
- Perform repeated checks. If the axes are parallel in both planes, then you are the owner of a level rooster.
- Remove the tools from the bike, put the wheel back in place and adjust the shifter.
If shifting is also problematic after the alignment procedure, try cleaning the rear derailleur cable.
Conclusion
When packing up before a long bike trip, put a tool kit in your backpack. This way you won’t worry about possible breakdowns and you can easily fix the situation. Then none of the train will not darken and will bring only positive emotions.
